Discovery of a 10 {mu}s isomeric state in {sub 63}{sup 139}Eu

Journal Article · Sat Jan 15 00:00:00 EST 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.83.014316· OSTI ID:21499338

Cullen, D M; Mason, P J. R; Kishada, A M; Procter, M G; Rigby, S V; Varley, B J ^[1]; Scholey, C; Eeckhaudt, S; Grahn, T; Greenlees, P T; Jakobsson, U; Jones, P M; Julin, R; Juutinen, S; Ketelhut, S; Leino, M; Leppaenen, A -P; Maentyniemi, K; Nieminen, P; Nyman, M ^[2]

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1. School of Physics and Astronomy, Schuster Laboratory, University of Manchester, Manchester M13 9PL (United Kingdom)
2. Department of Physics, University of Jyvaeskylae, Jyvaeskylae, FIN-40014 Finland (Finland)

Recoil-isomer tagging with the {sup 54}Fe+{sup 92}Mo reaction was used to establish a 10(2)-{mu}s isomeric state in {sup 139}Eu. Prompt versus delayed {gamma}-ray coincidence data have revealed the presence of a prompt rotational band built upon the isomer. The alignment properties of the states in this band show that the isomer is based upon a proton g{sub 7/2} configuration. The decay of the isomer takes place through a single 26-keV E1 transition. The {gamma}-ray transition strength for this decay is consistent with those established in the neighboring isomeric gamma-soft nuclei. In these nuclei, isomers are expected to form as a consequence of differences in nuclear shapes or configurations, and the natural hindrance associated with configuration-changing E1 transitions. The isomeric nature of the state in {sup 139}Eu is reasoned to be because of difference in shape of the proton g{sub 7/2} state and the proton h{sub 11/2} ground state to which it decays.

• OSTI ID: 21499338
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 83, Issue 1; Other Information: DOI: 10.1103/PhysRevC.83.014316; (c) 2011 American Institute of Physics; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALIGNMENT
CONFIGURATION
E1-TRANSITIONS
EUROPIUM 139
GAMMA RADIATION
IRON 54 REACTIONS
ISOMERS
KEV RANGE 10-100
MOLYBDENUM 92 TARGET
PROTONS
RECOILS
ROTATIONAL STATES
SHAPE
BARYONS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
ELECTROMAGNETIC RADIATION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EUROPIUM ISOTOPES
EXCITED STATES
FERMIONS
HADRONS
HEAVY ION REACTIONS
INTERMEDIATE MASS NUCLEI
IONIZING RADIATIONS
ISOTOPES
KEV RANGE
MULTIPOLE TRANSITIONS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
RADIATIONS
RADIOISOTOPES
RARE EARTH NUCLEI
SECONDS LIVING RADIOISOTOPES
TARGETS